Underfeed stoker



M. J. WIGHTMAN UNDERFEED STOKER Nov. 9. 1926.

Filed March 26. 1926 2 Sheets-Sheet 1 (inventor Pi-M Nov. 9 1926.

1,606,009 M. J. WIGHTMAN UNDERFEED STOKER Fil d M rch 26, 1926 2 Sheets-Sheet 2 lvwwtoz Patented Nov. 9, 1926.

UNITED STATES] PA'TNT orsics.

MERLE I. WIGHTMIAN, OF WEST NEW BRIGHTON, YORK, ASSIGNOR TO DOMESTIC STOKER COMPANY, OF NEW YORK, N. 1., A CORPORATION OF DELAWARE.

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Applicationfiled March' 26, 1926. Serial No. 97,538.

This invention relates to underfeed stokers for use particularly in domestic furnaces,

and consists of an improvement in the invention described in my prior Patent No. 1, 154,-

697, May 8, 1923. I

The underfeed stoker of my prior patent involves a fire pot into which the fuel, such for example as bituminou's'or other finely comminuted coal, is fed from the bottom, and a constantly rotating device for rotating the fuel within the fire pot. To minimize. friction this rotating device is mounted on ball bearings.

The structure describedin my patent operates satisfactorily under some conditions.

But under other conditions trouble has been experienced due to dust clogging up the ball bearings upon which the rotary device is mounted. i

The primary object of my present invention is to provide means for automatically cleaning and keeping clean the ball race in which the ball bearings are located.

Other and further ob'ects of my invention will appear more ful y hereinafter.

In the accompanying drawings, Fig. 1 is a vertical section of an underfeed devlce embodying my invention, and Fig. 2 is a plan view taken on the line-2-2 of Fig. 1.

I shall preface my description of the invention to which thisapplication is particularly directed, by a brief description of the underfeed device to which I haveapplied that invention.

As illustrated in the drawing, this device includes a fire pot 11 and means, such as the screw conveyor 12, for feeding fuel into that fire pot from the bottom. Jets 13 supplied with air under pressure through the concentric conduit 14, provide the necessary amount of forced draft for satisfactory combustion.

In burners of this type, when bituminous coal is used, it is found necessary to provide some means for agitating the bed to prevent excessive clinkering. vThe means shown in the drawing for accomplishing this function consists of the rotary stirrer 15. This stirrer, as shown, is preferably provided with a-plurality of vertical stirring rods 16 whichlie within the coal bedin the fire pot, and upon rotation of the-stirrer agitate the fuel sufficiently to avoid the formation of clinkers. The upper section of the fire pot, as shown, is provided with helical screw threads which have for their function the depression of ignited pieces of fuel to assist in the combustion.

Any suitable means may be provided for rotatingz'the stirrer 15, as for example the gears 1 18, 19 and 20. To minimize the power required for rotating the stirrer it is preferably mounted upon ball bearings 21 mounted in the ball race 22.

As described up to this point the structure shown in the accompanying drawings involves nothin novel as compared with the disclosure 0 m aforesaid patent.

As previously in icated, it has been found on occasions that difficulty is experienced in the operation of the structure of my patent by reason of the'fact that coal-dust which is present in large quantities is apt to find its way into the ball race designated in my present drawings as 22, and thus interfere with the rotation of the stirrer. My present invention has to do primarily with the avoidance of this difliculty.

The means which I have provided for accomplishing this purpose are best shownin Fig. 2 of the drawings. On reference to that figure it will be seen that instead of filling the ball race completely with ball bearings I have inserted into the race at several points, cleaning devices 23. These devices may take various forms, but as illustrated k. in thedrawings they consist of headless screw studs which have been'foun'd to be particularl eflicient because of the sharp edges pro uced by their threading. As shown in the drawings, I have inserted fourof these devices,but of course the particular number is not important except that sufficient should be provided to accomplish the desired result.

The'operation of these cleaning devices is doubtless understood from the above description- 'As the machine operates the balls travel about the'race and 1n doing so cause the cleaning devices to travel with them. These cleaning devices being of sufficient size to fill the ball .race almost'completely, scrape up whatever dust reaches the race and force it out through 'the channel 24 formed between the two members into which the race is cut. 'In this way the race is kept substantially free from coal dust and other foreign particles and interference with the operation of the ball bearing support for the stirrer is thus avoided.

The terms and expressions which I have employed are used as terms of description and not of limitation, and l[ have no intention, in the use of such terms and expressions, of excluding any mechanical equivalent of the features shown and described, or portions thereof, but recognize that various modifications are possible Within the scope of the invention claimed.

What claim is:

1. In a stoker, a rotating stirring member, a ball bearing supportfor said member including a ball race and balls, and means other than the balls located in said race for removing therefrom coal dust and other foreign particles.

2. In a Stoker, a rotating stirring member, a ball bearing support for said member including a ball race and balls, and a plurality eoaeoe of headless screw studs located in said race for removing therefrom coal dust. and other foreign particles.

3. In a ball bearing device particularly adapted for use in underfeed Stoker apparatus, a dust clearing member having the edge portions arranged to engage and substantially fit the curved Walls of a ball race- Way groove, said. member being adapted to move along the groove to clear obstructions therefrom. k

' 4. In a ball bearing, a groove clearing device comprising a scraper member adapted to be placed in a raceway groove between adjacent balls, said scraper member being arranged to move alon the groove under the impelling action of t e movin balls.

MERLE J. WI HTMAN. 

